understand that the juvenile foliage has greater surface area for photosynthesis to occur, so anytime a part of the tree or the whole tree gets chemical feedback to deploy its life support system, which is juvenile foliage, it does. So when the tree reaches its happy place it will start reverting back to scale foliage. Be patient.

Fertiliser cakes applied much like you would for a black pine. A couple to start with and then increasing the number every week or two until the soil surface is almost covered. I did read somewhere that fertiliser can induce juvenile growth but i wasn’t sure if there was much truth in that or not. I do remember seeing trees fed like this in Japan.

I wouldn't think that the regimen that you are using would knock the trees n to juvenile growth, more the pruning stressors, loss of foliage relative to root mass, signals indicating attack (as Nathan stated). I would pull some of the feeding back (add less than you normally would), the tree will grow its way out of the juvenile foliage, it just won't grow as quickly.

The other thing, one that has bitten me in the past, is to be sure that the tree has healthy roots and has been well repotted. Not just the pick the tree up out of the pot and trim the outside roots repotted, but actually worked do that over a 3-4 year period you remove all of the old soil, especially under the trunk and base of the tree, and replace it with good soil. Do 1/3-1/2 of the tree at each repotting. space them out 2-3 years, will really help over the long haul. Boon's Black Pine repotting video gives a good overview of the process, I hear that he is working on a Juniper project (DVD) now.